genirq: Remove IRQ_MOVE_PCNTXT and related code

Now that x86 is converted over to use the IRQCHIP_MOVE_DEFERRED flags,
remove IRQ*_MOVE_PCNTXT and related code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241210103335.626707225@linutronix.de